2KDL

NMR structures of GA95 and GB95, two designed proteins with 95% sequence identity but different folds and functions


Experimental Data Snapshot

  • Method: SOLUTION NMR
  • Conformers Calculated: 300 
  • Conformers Submitted: 20 
  • Selection Criteria: structures with acceptable covalent geometry 

wwPDB Validation   3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

A minimal sequence code for switching protein structure and function.

Alexander, P.A.He, Y.Chen, Y.Orban, J.Bryan, P.N.

(2009) Proc Natl Acad Sci U S A 106: 21149-21154

  • DOI: https://doi.org/10.1073/pnas.0906408106
  • Primary Citation of Related Structures:  
    2KDL, 2KDM

  • PubMed Abstract: 

    We present here a structural and mechanistic description of how a protein changes its fold and function, mutation by mutation. Our approach was to create 2 proteins that (i) are stably folded into 2 different folds, (ii) have 2 different functions, and (iii) are very similar in sequence. In this simplified sequence space we explore the mutational path from one fold to another. We show that an IgG-binding, 4beta+alpha fold can be transformed into an albumin-binding, 3-alpha fold via a mutational pathway in which neither function nor native structure is completely lost. The stabilities of all mutants along the pathway are evaluated, key high-resolution structures are determined by NMR, and an explanation of the switching mechanism is provided. We show that the conformational switch from 4beta+alpha to 3-alpha structure can occur via a single amino acid substitution. On one side of the switch point, the 4beta+alpha fold is >90% populated (pH 7.2, 20 degrees C). A single mutation switches the conformation to the 3-alpha fold, which is >90% populated (pH 7.2, 20 degrees C). We further show that a bifunctional protein exists at the switch point with affinity for both IgG and albumin.


  • Organizational Affiliation

    Center for Advanced Research in Biotechnology, University of Maryland Biotechnology Institute, Rockville, MD 20850, USA.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
designed protein56N/AMutation(s): 0 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
Sequence Annotations
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: SOLUTION NMR
  • Conformers Calculated: 300 
  • Conformers Submitted: 20 
  • Selection Criteria: structures with acceptable covalent geometry 

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2009-12-29
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Version format compliance
  • Version 1.2: 2022-03-16
    Changes: Data collection, Database references, Derived calculations